Soot Oxidation Activity of Redox and Non-Redox Metal Oxides Synthesised by EDTA–Citrate Method

Effect of ionic radius on soot oxidation activity for ceria‐based binary metal oxides

“…AR grade chemicals were used for the synthesis of metal oxides. An EDTA–citrate complexing method reported earlier was used to synthesise all the binary metal oxides. A black precursor solid obtained after heating at 150°C/24 hr in the oven was further calcined at 350°C/12 hr and 600°C/5 hr in air to obtain the required oxides.…”

“…The peak deconvolution was done using CasaXPS software. Further instrumental details are provided in previously reported work …”

“…The synthesised binary metal oxides were utilised as catalysts for soot oxidation reaction using standard Printex‐U (carbon black, produced from the combustion of natural gas by Orion Engineered Carbons, used as a model compound for diesel soot). The catalyst and soot were made into tight contact for 30 min with a catalyst:soot ratio of 4:1 . Bound moisture content was removed by preheating the sample at around 200°C.…”

“…The prepared soot and catalyst mixture was loaded in a TG/DTA 6300 thermogravimetric analyser instrument and operated in a temperature range of 200°C –600°C with a heating rate of 10°C/min. Air flow at 100 ml/min was maintained for preheating and normal reactions . The repeatability and order of the reaction were checked for multiple reactions.…”

“…For redox metal oxides, reduction temperature, ionic radius difference, and surface oxygen binding energy control the soot oxidation activity. On the other hand, for nonredox metal oxides, it is the ionic radius, lattice strain, and surface area that control the activity . From the study, it is prominent that a common parameter of ionic radius affects the metal catalyst activity.…”